Furnace-grate



' (No Model.) 2 Sheets-Sheet 1.

W. W. CHURCHILL.

FURNACE GRATB.

Pat ented Apr. 20, 1897.

Z .Z J m/ m a M 7 .m .h M L (No Model.) 2 Sheets-Sheet 2.

W. W. CHURCHILL.

FURNACE GRATE.-

w m w L p UNITED STATES PATENT 1? tries.

WVILLIAM W. CHURCHILL, OF NEW YORK, N. Y., ASSIGNOR TO THE VVEST-INGHOUSE, CHURCH, KERR & COMPANY, OF ORANGE, NEW JERSEY.

FU RNACE-G RATE.

SPECIFICATION formingpart of Letters Patent No. 581,061, dated April 20,1897.

Application filed June 29, 1896.

To a/ZZ whom it may concern.-

Be it known that I, WILLIAM W. CHURCH- ILL, of New York, in the countyof New York and State of New York, have invented certain new and usefulImprovements in Furnace-Grates and I do hereby declare thatthe followingis afull, clear, and exact description thereof, reference being had totlrf'accompanying drawings, and to the letters of reference markedthereon, which form a part of this specification.

This invention relates to improvements in grates for furnaces of thatclass wherein a plurality of bars are arranged transversely of thefurnace in an inclined or stepped position, the front edge of oneoverlapping the rear edge of the subjacent bar, as illustrated generallyI in Letters Patent Nos. 409,304, 409,305, and 409,650, granted toWilliam R. Roney on the 20th day of August, 1889.

Among the objects of the invention are to simplify, improve, and cheapenthe construction of the grate-bars, to produce a grate-bar betteradapted to stand the heat of the furnace and which is therefore moredurable,

and to so construct and arrange the bars that their interaction willtend to break up and prevent the accumulation of clinkers, and willthereby promote the free burning of the fuel. Various other advantagesare obtained by the construction set forth, as will hereinafter morefully appear.

The invention consists in the matters hereinafter described, and moreparticularly pointed out in the appended claims, and it will be readilyunderstood by reference to the accompanying drawings, in which Figure 1is a longitudinal vertical section through the front part of the furnaceand of the grate therein, showing the arrangement of the fuel-feedingdevices. Fig. 2 is a detail in elevation, as seen from the front of thefurnace, of one of the grate-bars used at the upper part ofthe grate,the two parts of which the same is composed being slightly separated todisclose the construction more clearly. Fig. 3 is a top plan view of thetop plate of the bar shown in Fig. 2. Fig. 4 is a transverse verticalsection of the bar shown in Figs. 2 and 3. Fig. 5 is a detailfragmentary view of the grate-bar shown in Fig. 4, show- Serial No.597,287. (No model.)

ing the rear or fire-box edge thereof. Fig. 6 is a view similar to Fig.t of one of the bars used at the upper part of the grate. Fig. 7 is aview similar to Fig. 5 of the grate-bar shown in Fig. 6. Fig. 8 is adetail plan view of the top plate shown in Figs. 6 and 7. Fig. 9 is aview similar to Fig. 4, but showing the parts of the bar detached toindicate more clearly the construction of the interfitting rib andgroove of said parts.

First referring briefly to the general illustration given in Fig. 1, Aindicates one of the side walls of the furnace, B the front wallthereof, and C a portion of the bridge-wall.

D indicates the lower part of the side bearer, which rests on thefurnace-floor opposite the foot or dumping grate. Said dumping-grate isomitted, as not concerned in the present invention, but occupies, whenin place, a horizontal position extending transversely across thefurnace at the bottom of the main grate, as shown in said prior patents.

E indicates as a whole an inclined grate composed of rocking barsembodying one feature of the present'invention.

.F is an external coal hopper or magazine, and G a dead-plate forming aninward extension of the inclined bottom F of the coalhopper.

The grate E, as shown clearly in Fig. 1, is composed of a series oftransversely-arranged horizontal grate bars E E, arranged in steppedorder with the rear edge of each bar overhanging the front edge portionof the next bar below it. Each bar Eis provided at its ends withtrunnions e e, which rest in notches d, formed in the inclinedsupportingplates D, secured at the opposite sides of the fire-boxadjacent to the side walls of the furnace. Preferably, and as shown inthe present instance, the supporting-plates D are formed in one piecewith the side bearers D for the foot-grate.

Each of the several grate-bars consists of two main portions, comprisinga relatively thin vertical web-shaped body portion E made'of skeletonform, as shown, so as to re duce the weight of the bar, facilitate thepassage of air therethrough to the fire, and provide suitable access fora slicing-bar for stoking the fire, and atop plate E suitably securedupon the upper edge of said body portion and having an upper surfaceconsisting in the instance shown of a substantially horizontal frontportion 6 and a rearwardly-inclined rear portion 6 The trunnions c c ofthe grate-bars are of novel form, being made oval or elliptical incross-section,with the longer axis of the ellipse disposed vertically,and are also made tapering outwardly, as indicated clearly in Figs. 2and 4:, while the notches or recesses d in the side plates D, whichreceive said trunnions, are correspondinglytapered, but made circularand formed on a radius somewhat larger than half the minor axis of theellipse of said trunnions, so as to afford spaces at either side of thetrunnions to permit the latter to have a rocking movement therein. Theresult of this construction is that the oscillatory movement of thetrunnions tends to keep the bearings practically free from coal, ashes,and dust, inasmuch as any particles which are small enough to drop intosaid trunnionnotches are rapidly crushed or ground int-o fine powder bythe rocking movement of the trunnions in their bearings, andtheinwardlyinclined bottoms of said recesses insures that the dust orpowder thus formed will work downwardly and out of the hearing.

The lower member ll of the grate-bar is provided at its upper edge witha plurality of bearing-surfaces c c c, arranged in this instance one ateach end and one atthe center thereof. Vithin said surfaces are form edlongitudinally-arranged notches c, adapted to receive a correspondingrib 6, formed centrally upon the under side of the upper memher or topplate E The bearing-surfaces c c e" are elevated above the edge of thebar, so as to form open spaces or slots between the bar and the topplate; The bearing-surfaces c c are formed in part by lugs 6 whichextend horizontally forward or toward the front of the furnace, beneaththe front part of the top plate, through which latter are inserted boltsa which also extend through suitable vertical apertures in said lugs,the top plate being countersunk around the bolt-apertures to receive theheads of the bolts a which are flush with the surface of said plate.Said top plate is provided on its under side with a series ofclosely-spaced transversely-arranged depending flanges or ribs 8' c,which extend in a direction from front to rear of the plate. Said ribsare so located and the bars are so arranged with relation to each otheras to cause the rear or inner parts of the ribs of one bar to overhangand extend adjacent to the top surface of the front portion of thesubjacent bar so that when said bars are oscillated in one directionsaid ribs will be brought down in to contact, or nearly so, with thesurface of the subjacent bar, thereby serving to crush and break up anyclinker or coal which may be resting upon that part of the bar. Thisaction obviously keeps each bar free from adherent clinker and allowsthe fuel to pass freely downward over the grate during the reciprocatorymotion of the bars. Those ribs 0 which are transversely opposite thelugs e c 0 will obviously only extend from the rear side of thegrate-bar forwardly to the rear edges of the lugs, as indicated in Figs.8 and 4:.

The ribs 6 are shown as made with obtuseangular edges at the lowermargin of their forward end portions, as shown at 6 the said angularsides serving to improve the crushing or breaking action of the ribs.The front parts of the ribs c" serve more especially to increase theamount of cooling-surface of the grate-bar and stiffen the same in a wayto prevent warping or twisting thereof.

In order to prevent the fine coal and slack from falling through betweenthe grate-bars, the front edges of each of the first or upper sixgrate-bars are provided with an upturned flange c ,such ashas beencommonly and heretofore used. This flange is omitted from the lowergratebars, inasmuch as it is found in practice that the fine coal whichremains uncensumed is sufficiently coked before it reaches this part ofthe grate to prevent its falling through between the bars.

Upon the lower edge of the vertical web or main body portion of eachgrate-bar is formed a depending lug or arm c of cylindric form at itsend and adapted to rest within a correspondingly-shaped recess 7!,formed in the upper edge of the reciprocating grate-actuating bar H. Inorder to support said bar II in position beneath the grate-bars with itsseveral notches 7t engaged with the arms e of said bars, the bar H isprovided at points intermediate of its length with laterally-offsetportions h h, arranged opposite the depending lugs or arms 6 of two ofthe gratebars and provided with apertures 7L2 hiform ed in axialalinement with the centers of the cylindrie ends of said arms, andthrough which extend stubs c formed or mounted upon said arms. Suitablekeys or pins 0 are inserted through the ends of said studs to retain thebar II in position thereon.

An actuating mechanism for giving motion to the bar H is shown in Fig.1, the same consisting of a rotating shaft J, mounted in brackets J andprovided with a crank J which is connected by a bar K and with a leveror arm L, mounted at its upper end on a rock-shaft M, the lower end ofsaid arm L being connected with the bar II by means of a connecting-rodI, which is pivoted to the bar II and has sliding connection with thearm limited by means of nuts i 2', which serve as tappet-shoulders forcontact with the said arms, and the adjustment of which on the red Ienables greater or less motion to be given to the bar II, as desired.

The particular form of grate-bar shown, in which the top plate thereofis provided with a series of closely-spaced depending flanges or fins,is of importance, inasmuch as said ribs not only serve to prevent thegrate-bar from warping under the excessive heat, but also afiord a verylarge cooling-surface, which is exposed to the cool air beneath thegrate and prevents the top plate from becoming overheated. At the sametime the construction is such as not to interfere materially with thestoki-ng' of the fire from the front of the furnace should this becomenecessary.

I claim as my invention- 1. A grate having a plurality ofpivotallymounted overlapping grate-bars having on their under surfacesdepending transverse ribs or flanges opposed to the rear parts ofsubjacent bars, and means for actuating said bars on their pivots.

2. A grate having a plurality of pivotallymounted overlapping grate-barshaving on their under surfaces depending transverse ribs or flangeswhich extend from the front to rear edges of the bars and are opposed tothe front parts of the subjacent bars at their rear portions, and meansfor oscillating said bars on their pivots.

3. A grate provided with a plurality of pivotally-mounted, overlappingskeleton gratebars, each having a fuel-supporting top plate provided onits under side with a series of transversely-arranged, closely-spaced,depending ribs or flanges, and means for oscillating said bars on theirpivots.

4. A grate having a plurality of pivotallymounted overlapping.gratebars, consisting of top plates and stiffening-Webs made separatefrom each other, the webs being adapted to form openings or slotsbetween their upper edges and the bottom surfaces of the top plates andsaid top plates being provided with trans-.

verse depending ribs or flanges, and means for oscillating said bars ontheir pivots.

5. A grate having a plurality of pivotallymounted, overlappinggrate-bars, each comprising a main body portion having the form of avertical Web provided at its upper edge with laterally-extendedsupportin g parts, and a fuel-supporting plate secured horizontally uponsaid main body, said fuel-supporting plate being provided on its underside with a series of transversely arranged, closelyspaced dependingflanges, and means for oscillating said bars upon their pivots.

6. A grate having a plurality of pivotallymounted, overlappinggrate-bars, each comprising a main body portion having the form of avertically-arranged skeleton web provided at its upper edge withlaterally-extended supporting parts, each provided with alongitudinally-arranged groove in its top surface, and a fuel-supportingplate located horizontally upon said main body portion and provided onits under surface with alongitudinally-extended rib adapted to fitwithin and engage the notches in said body portion, and also a series oftransversely-arranged, closelyspaced integral depending flanges, andmeans for oscillating the bars on their pivots.

I 7. The combination, in a furnace-grate, of a series ofpivotally-supported grate-bars arranged transversely of the furnace instepped order and provided on their under surfaces withtransversely-arranged closely-spaced depending flanges arranged to coactwith the upper surface of the subjacent grate-bar to crush the fuellying upon the latter when said grate-bars are oscillated,and actuatingmeans connected with said bars for oscillating the same simultaneously,substantially as set forth.

8. In a furnace-grate, the combination of grate-bars provided withtrunnions oval in cross -section and also made tapering outwardly and aside support provided with circular, correspondingly-taperedbearing-recesses adapted to receive and support said trunnions,substantially as described.

In testimony that I claim the foregoing as my invention I afliX mysignature, in presence of tWo witnesses, this 26th day of May, A. D.1896.

WILLIAM W. CHURCHILL. Witnesses:

FRANCIS E. FROTHINGHAM, ALVANO T. NIOKERSON, Jr.

